| 摘要 |
PURPOSE:To facilitate the magnetization of the permanent magnet of a rotor and reduce the unevenness of the characteristic, by magnetizing the permanent magnet with skew at a specified angle, and by setting a magnetism-sensitive element so that the polarity of a central section in the axial direction of the permanent magnet may be detected. CONSTITUTION:A rotor 1 having a permanent magnet 2 is organized by fixing the permanent magnet 2 on the internal peripheral wall of a cup-formed yoke 3, and a rotary shaft 4 on the center of a bottom section. The permanent magnet 2 is alternately magnetized in the circumferential direction. So far as the state of this magnetization is concerned, one side of two different pole boundaries formed in the range of the electrical angle of 360 degrees is skewed at the electrical angle of 120 degrees. Besides, a magnetism-sensitive element 12 is set so that the polarity of a central section in the axial direction of the permanent magnet 2 may be detected. |
